The White House said today it was "outraged" that Ukrainian forces had turned automatic weapons on demonstrators as a short-lived truce shattered in Kiev.
In a statement, White House press secretary Jay Carney called for the withdrawal of government forces from the front lines in the Ukrainian capital, but did not specify what consequences there would be from Washington after its previous, repeated calls for an end to violence were ignored.
"We are outraged by the images of Ukrainian security forces firing automatic weapons on their own people," Carney said.
"We urge President (Viktor) Yanukovych to immediately withdraw his security forces from downtown Kiev and to respect the right of peaceful protest, and we urge protesters to express themselves peacefully."
Carney urged the Ukrainian military not to get involved in a conflict that he said should be resolved by political means and said Washington would work with its allies to hold to account those responsible for violence.
Yesterday, Obama warned Ukraine's government of "consequences" if it did not stop turning violence on peaceful protestors.
The administration also put 20 top Ukrainian officials on a visa blacklist and threatened further sanctions.
But fresh violence erupted earlier today, with raging street battles between protestors and security forces.
More than 60 protesters died from gunshot wounds, according to an opposition medic, making the day the bloodiest since Ukraine's independence.
